Iron-Containing Seed Particles Enhance α-Pinene Secondary Organic Aerosol Mass Concentration and Dimer Formation
Year: 2024
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Secondary organic aerosol (SOA) comprises the majority of submicron particles and is important for air pollution, health, and climate. When SOA mixes with inorganic particles containing transition metals (e.g., Fe), chemical reactions altering physicochemical properties can occur. Here, we study Fe’s impact on the formation and chemical composition of SOA formed via dark α-pinene ozonolysis on either (NH 4 ) 2 SO 4 or Fe-containing (NH 4 ) 2 SO 4 seed particles and aged at varying relative humidities (RHs). Aerosol composition was determined using online extractive electrospray ionization mass spectrometry, providing high-resolution chemical and temporal identification of monomers and dimers in the SOA. At high RH, Fe’s presence resulted in higher particulate SOA mass concentrations (117 ± 14 μg m –3 ) than those formed in its absence (70 ± 1 μg m –3 ). Enhanced mass is coupled with more dimers (C 15–20 ’s), attributed to Fenton-driven oligomerization reactions. Experiments with Fe 3+ -containing seeds showed similar chemical composition and enhanced SOA mass, suggesting a dark reduction pathway to form Fe 2+ in the presence of SOA. Overall, Fe’s presence at high RH lowers SOA volatility and enhances particulate organic mass and condensed phased reactions of higher volatility species that would normally not participate in SOA formation, which may be important when considering its formation in air quality and climate models.
Institution: Paul Scherrer Institute
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Awards: International, Interdisciplinary & Intersectoral Postdoctoral Fellowships at the Paul Scherrer Institut, The interplay between reactive oxygen species and the multiphase chemistry of nitrogen, halogen and secondary organic species in aerosol particles, Solutions for Sustainable Access to Atmospheric Research Facilities, International, Interdisciplinary and Intersectoral Postdoctoral Fellowships at the Paul Scherrer Institut, G5578714457, Ultra-high resolution mass spectrometer – Orbitrap-MS, Particle formation from complex organic transported mixtures at CLOUD, Molecular dIffusion of organiCs in secondaRy Organic aeroSols and impaCts On Particle chEmistry, Molecular dIffusion of organiCs in secondaRy Organic aeroSols and impaCts On Particle chEmistry
OpenAlex ID: W4402397752